Extruded tubular wall and method of making same



April l5, 1929- 3 w. M. FULTON V 1,709,011

EXTRUDED TUBULAR WALL AND METHOD OF MAKING SAME Filed Jan. 14, 1922 2 sheets'sheet 1 t i4 A n f4 7 IIIIIIIM M f6 7i l `v '7.5 y i 1f l Irv/Q \:/7

i April l16, 1929. w. M. FULTON EXTRUDED TUBULAR WALL AND METHOD OF MAKING SAME Filed Jan, 14 1922 2 Sheets-Sheet Fllf( Patented Apr. 16, 1929.

UNITED STATES PATENT OFFICE.

i WESTON FULTON, F KNOXVILLE, TENNESSEE, ASSIGNOE. T0 THE FULTON SYLPHON COMPANY, 0F KNOXVI-LLE, TENNESSEE, A CORPORATION 0F DELAWARE.

nxraunnn TUBULAB WALL AND METHOD or MAKING SAME.

Appucaatn'mea January 14, 1922. serial No. 529,282.

rlhis invention relatesto 'flexible corruof the cold working operations so that the gated tubular walls, and methods and ap- Xresulting tubularwall is composed of a paratus for making the same. v plurality of lzones having different physlVhile a variety of methods have hereical characteristics. On the other hand, the a tofore been suggested for producing relabottom of the blank is subjected to each antively thin tubular blanks in which are to be nealing operation although not possessing formed relatively deep corrugations to renthe physical characteristics obtained by cold der the tubular wall flexible in thedirection Working the metal, which tends to produce of its axis, the method universally employed undesirable eifects, while, as successive zones l@ in making these blanks, so far as I am aware, of the bottom of the original cup are worked is that disclosed in my Patent No. 1,049,572 over into the tubular wall during successive dated J an. 7, 1913, because ofthe superior drawing operations, the successive zones of durability and flexibility obtained by the the tubular wall from the bottom up have practice of the process .there disclosed.

Notwithstanding the superiority of this at1ons, progressively decreasing in number', method of producing relatively thin tubular before they are subjected to any cold work- .blanks in the manufacture of `'flexible corruing operation.

gated tubular walls Iover methods previous- Therefore the physical characteristics of 1y Suggested, there are certain inherent de the metal in the successive zones is not the feats in this method of procedure which af- Same and the flexibility and durability of the feet the physical characteristics of the remetal differs in the different zones. As the sulting flexible walls and which more parlife of a tubular wall of this character is no ticularly tend to` limit their' capacity to withgreaterthan the life of the weakest corrustand repeated flexure without rupture. gation, the life of the walll iS determined lEach time that the blank is subjected to a 'by the durability of the weakest zone prodrawing operation which vreduces the diduced in the tubular wall by the successive ameter ofthe same-and it is customary to cold Working and annealingoperations. subject the blank to a number of drawing 1t iS an object of this invention to prooperations so as to reduce the diameter and Vide a method for making flexible corruil@ thickness of the blank by smally increments gated tubular Walls which avoids the produc- "and thereby avoid imposing undue strain tlon 0f a blank having a plurality of zones upon the metal in its wallsa portion f of different physical characteristics and the end of the blank is worked over into which produces a wall of more uniform the tubular Wall. As the entire tubular wall flexibility and durability throughout. is subjected to cold working during each Owing to the relatively large friction bedrawing operation, whilethe bottoni wall tween the contacting surfaces of the punch is substantially unaffected, it follows that and die, it is common practice to make the the tubular Wall is composed of a plurality lower end of the punch somewhat smaller of zones` each of which is subjected "to one f than the upper end, i. e. give the punch a less cold working operation, from theI top slight taper, so as to `facilitate the withdrawto the bottom.

dii

llt is also customary to subject the blank sults in the drawn blank being somewhat to an annealing operation between some or thicker at its bottom or closed end than at all of the drawing operations so as to reits upper or open end. To. eliminate this move the brittleness which is producedin inequality in thickness it is necessary to the metal by the drawing operation. Expepass the blank through a final drawingoprience has demonstrated that these annealing eration which employs a punch of uniform operations do not eliminate all of the effects diameter,` and during this operation to draw been subjected to repeated annealing operal of the blank from the punch, which rel the exdess metal in the lower portion of the vblank into the upper portion of the tubular wall. This operation not only subjects the tubular wall to an unequal cold working operation but it also tends to upset the distribution -of the physical characterlstics ob- 'tained bythe preceding operations.

lnessin the first instance.

It is a further object of this invention to provide a method for making flexible corrugated tubular walls which substantially eliminates the llikelihood of elongated blow holes o r gas pockets being lformed in the resulting flexible wall.

It is'a further object of this inventiomto.-

provide a method for making flexible corrugated tubular Walls whereby the same may i have a relatively thick end flange integrally connected with the tubular wall without the disadvantages and defects vinherent in the process heretofore employed for forming a thick end flange integral with the tubular wall.

Another object of this invention is to provide an improved method for making flexible corrugated tubularrwalls whereby the same may have a closed end wall integral with the tubular wall, and thereby avoid the necessity of soldering, brazing 0r otherwise attaching an end wall to the tubular wall as well as the weakness at the junction of the end wall with the tubular wall incident to such processes for forming the end Wall integral with the tubular wall.

Another object of this invention is to provide in the manufacture of flexible corrugated tubular walls an improved method for displacing the grain of the metal at an angle to the axis of the tubular wall.

Another object of this invention is to provide a lmethod for making flexible corrugated tubular walls whereby a relatively thin tubular blank of substantially the thickness suitable for forming the flexible corrugations may be `produced in a single opertion.

Another object of this invention is to provide a flexible corrugated tubular wall of extruded metal, or of metal which is both extruded and drawn, ,and which may have either a closed end wall, or a relatively thick cndlan'ge, or both, integral with the tubular wall and which, also, either with` or without said integral end elements, may have the rain of the metal disposed at the desired ange to the axis of the tube.

Another object of the present invention is to provide improved apparatus for displacing the grain of a relatively thin tubular blank at an angle to its axis.

Other objects will appear as the description of the invention proceeds.

The invention is capable of being carried out in a. variety of ways 'some of which are illustrated in the accompanying drawings and described hereinafter, but it is to be expressly understood that the selected embodiments have been chosen for purposes of illustration only and that reference is to be had to the appended claims for a definition of the limits of the invention.

Referring in detail to the drawings, wherein the same reference characters are used to designate the corresponding parts in the several gures, and wherein for the sake rof c'learness the tubular wall is shown as of a thickness disproportionate to its other dimensions,-

Fig. 1 is a diagrammatic view illustrating a suitable blank and apparatus for extruding the same;

Fig. 2 is a corresponding view illustrating the blank after the same has been extruded;

Fig. 3 is a corresponding view illustrating a means for applying a drawing force to aid in the extrusion of the blank;

Fig. 4 is a fragmentary elevation, partly in section, of suitable apparatus for displacing the grain of the blank;

Fig. 5 is an end elevation of the strue- `ture shown i'n Fig. 4;

Fig. 6 is a schematic view to illustrate the displacement of the grain; and

Fig. 7 is a diagrammatic view of a completed corrugated flexible tubular wall provided with a relatively thick integral flange and an integral end wall. Y

In accordance with the present invention, a relatively thin tubular blank is formed by extruding the metal through a suitable die. The extruding step of my method may be carried out in any suitable way, as for example in the manner disclosed in the patent to Lee No. 822,285 of June. 5, 1906 or in the patent to Hooker No. 922,585 of May 25, 1909. A blank 10, of any suitable shape and material, but preferably of generally tubular formation, and made in any suitable wav, as-by forging, drawing, machining, ete., .is posltloned in any sutiable apparatus for extruding the same, diagrammatieally shown in Figs. 1 to 3 as comprising a die 1l, having an enlarged bore 12 of substantiallv the external diameter of the blank 10 and a reduced bore 13 of the diameter to be given .the extruded blank, and a punch 14 mounted in the ram of any suitable press (not shown) and provided with a pilot portion 15. 'lhe punch 14 has substantially the same diameterI as the enlarged bore 12, while the diameter of the pilot portion corresponds with 4the internal diameter to be given the extrudthe blank 10 when the shoulder 16 between the punch contacts with the upper edge ofy l said blank.

Pressure is then applied to the upper edge of the blank by the shoulder 16 on the punch 14 and the blank 10 is extruded through the bore 13 into a relatively thin elongated tubular wall the `external and internal diameters of which are determined by the diameter of the bore 13 and of t-he pilot portion 15 respectively. During this extruding operation the metal of the blank 1() is subjected only to pressure which tends to compact and density the same and, the blank being entirely confined between the die and punch during the extruding operation, it may be worked in a single operation into a relatively thin tubular wall which has substantially the pleted Wall and thereby the completed flex? without the likelihood of a line of weakness i thickness suitable for forming the flexible corrugations.

When it is desired that the finished wall have av closed end wall integral with the tubular wall, the end wall 17 of the blank may be suitably formed of substantially' the thickness desired in the end wall of the comible wall may be provided with an' integral end wall without additional operations or at the junction of the same with the tubular wall.

ln extruding the blank 10 the open end may be left with a zone of substantially the Hilti thickness of the original blank as shown at 18, which may be subsequently flanged over or otherwise suitably formed to constitute means of attachment, whereby may be provided a relatively thick end flange which is integral with the tubular wall and which at the same time gradually tapers into said tubular wall and thereby avoids the line of weakness at this place which characterizes Atermed only by the junction of the end portion with the tubular Wall where the latter has been formed integrally by drawing operations only.

While the tubular blank 19 with its relatively thin elongated tubular Wall 20 may be the method of extrusion, I

' have found that a somewhat greater strength and resilient texture can be given to the tubular Wall-by aiding the passage of the ltion, of the pressure of the tongs 23 for firmly gripping said projection 21. As illustrated in this figure, the weight 22 with its tongs 23 may be elevated into operative position by a table 24 on a piston 25 which works in the cylinder 26 of any suitable pneumatic, hydraulic or other hoist.

The table 24 is first elevated by the piston 25 to such a position that the tongs 23 grip the projection 21, after which the table 24 is. withdrawn, leaving the Weight 22 suspended from the projection 21 and constituting a drawing force tending to draw the blank through the `extruding die 11. Pressure is then applied to the extruding punch 14 as in the method heretofore described and the blank 10 is extruded through the bore 13 of said die lunder the combined lacpunch 14 on one end of the blank 10 and thejpull of the drawing force on the other end of said blank. It is to be expressly understood that, while a projection 21.011 the 'closed end wall of the blank 10 has been shown, any other suitable means may be employed for applying a drawing force to the blank to aid its passage through the die 11 under the extruding pressure. When a projection 21 is employed, it may be planed olf after the tubular wall has been completed, leaving the end wall 17y integralqwith the tubular Wall, it desired.

In making relatively thin tubular blanks for flexible corrugated tubular walls of nonferrous metals, such as copper and certain grades of brass, the ext-ruding operation, or the combined extruding and drawing operation, is preferably carried out as a cold working operation, i. e. at a temperature not appreciably above atmospheric tempera-ture.

In the case of some metals, however, such as cupro nickel and steel for example, the extruding operation, or the combined extruding and drawing operation, may be performed upon a hot blank, i. e. one that has been heated to a temperature appreciably /above atmospheric temperature.

A relatively thin tubular blank vproduced I by the method heretofore described has its grain extending parallel to the axis of the tube Whereas, as pointed out in my prior Patents No. 1,049,572 dated J an. 7, 1913 and No. 967,010 dated Aug. 9, 1910, it is desirable to have the grain of the blank disposed at an angle to the axis of the tube so that the greatest strength of thle metal approximates in direction the resultant of the forces to which the metal is subjected when in use. Therefore, I preferably subject the 'relatively thin extruded, or extruded and drawn, wall to a treatment whereby the grainV is displaced angularly of the axis ofthe tube. Any suitable method may be employed to accomplish lthis result, the preferredv procedure being to pass the blank through a CFI tation between the blank and the die, so as to uniformly displace the grain ofthe metal in the tubular wall while slightly reducing its thickness.

Any suitable apparatus may be employed for effecting the relative rotation of the blank and die as the former is drawn through the latter. A'One suitable apparatus for accomplishing this result is shown somewhat schematically in Figs; 4 and 5 wherein 30 designates the ram or punch holder of a press of any suitable construction, which ram or punch holder is appropriately' reeiprocated inthe ways 31, as by the crank 32. The ram or punch holder 30, in the form shown, is composed of two secctions (see Fig. a main recessed body portion33 and a recessed cover portion 34 which maybe secured to the body portion/33 in any suit-able way, as by the cap screws 35. Mounted in the ram is a rotatable punch or mandrel holder 36v which is provided inthe recess 37 with an enlarged portion 38 that carries, preferably integrally therewith, a bevel gear 39. Projecting beyondthe bevel gear 39 is an extension 40 of reduced diameter which is received within and centered by a cylindrical recess 41 communicating with the main recess 37, said recess 41 constituting a bearing for the Areduced end of the rotatable punch or mandrel holder 36. A ball bearing 42'of any suitable construction is also preferably interposed as a thrust bearing between the bevel gear 39 and the end of the recess 37. Meshing with the bevel gear 39 isi a second bevel gear 43 on xa short stub shaft 44 which projects laterally of the ram 30 and carries at its outer end a small pinion 45 which meshes with a rack 46 pro vided`in any suitable way on one of the ways 31. holder 36 which projects outwardly from the ram 30 is suitably constructed for at tachment of a drawing punch or mandrel. In the form shown, the holder 36 is provided with a threaded recess 47 to receive the threaded end of the punch or mandrel 48, a screw 49 being employed to secure the mandrel lixedly within its holder. Mounted on the bed 50 of the press is a drawing die 51 of any suitable construction in alinement with the path of reciprocation of the mandrel 48.

A tublar blank 19 made in either of the manners heretofore dcscribedand of a thickness slightly in excess of thatdesired for the finished wall is mounted on the mandrel or punch 48 when the ram 30l is in its upper position and the press is then started to lower the ram and force the blank 19 on the mandrel 48 through the die 51. As theraln descends, the pinion 45 by coaction with the rack 46 rotates the stub shaft 44 whereby. the bevel gear 43 rotates the bevel gear 39 and the holder 36 secured thereto. Therefore,

The end of the punch or nrandrelJ the mandrel 48, together` with the blank 19 supported thereon, is rotated at the same time that it is moved longitudinally, so that relative rotation is maintained between the blank and the 'die at the same time that the bla-nk is moved longitudinally with respect to the die.l The thickness of the tubular wall of the blank is thereby slightly reduced while, at the same time, the metal in said tubular wall is displaced angularly so that the grain of the metal is displaced shelically as shown diagranimatically by' the dotted lines 52 in Fig. 6. Vhen the blank has been passed through the die 51 it may be removed from the mandrel 48 so as not to be subjected to the action of the die as the mandrel is rotated reversely and withdrawn through the same, or any suitable means may be interposed in the train of gearing for rotating the holder 36 so that withdrawal of the mandrel is not accompanied by rotation of the same.

By suitably proportioning the gearing in the train for. rotating the mandrel 48, the extent to which the blank is rotated as it is moved through the die 51 may be proportioned to so displace the grain of the tubular wall that said grain will lie at the desired angle to the axis, whereby it will approximate in direction the direction of the resultant of the forces to which the flexible wall is subjected when in use--an angularity which will vary with the diferent uses to which a wall of this character is applied. While the present invention is not limited to the above described method of displacing the grain angularly of the axis of the tube, this method possesses the advantage that the grain is uniformly displaced throughout the length and circumference ofthe tube so that it lies at the same angle to the axis throughout the tubular wall. of procedure possesses a marked advantage over the method disclosed in my Patent No. 1,049,572 above referred to, because in a tube produced by the method of my prior patent the grain lies parallel to the axis of the tube along two lines diametrically disposed with respect to each other, while in the neighborhood of these lines the angularity of the grain with respect to the axis is relatively small and gradually increases to lines 9()O removed from the aforesaid lines. The present method, on the other hand, displaoes the grain at a Substantially uniform angle throughout the tubular wall of the blank, and this angularity of the grain can be controlled by proportioning the extent of rotation to the extent of longitudinal move' nent of the blank so that the direction of maximum strength of the metal may approximatethe direction of the resultant forces to which the same is subjected.

The relatively thin extruded, or combined extruded and drawn, wall, with its grain Thereby this method l both formed integrally preferably displaced angularly of the axis of the tube as just explained, is then provided with relatively deepr or flexible corrugations to render the same flexiblein the direction of its axis. TheY corrugating operation may -be carried out in any suitable way, as by themethod disclosed in my prior Patent No. 971,838 dated October 4, 1910 or by the method disclosed in the application filed by Jean V. Giesler and myself `Serial No. 390,981 dated June 22, 1920. A flexible corrugated tubular wall produced by the process heretofore described is diagrammatically illustrated in Fig. 7, said wall also being shown as provided with a closed end wall' and la' relatively thick attaching end flange with the tubular wall as heretofore described.

It will therefore be perceived that a `method of making flexible corrugated tubular walls has been provided whereby the tubular wall is nov longer composed of a plurality of zones which have been subjected to dif- .ferent degrees of cold workingand different conditions of annealing so that they possess different physical characteristics. Morcover, a relatively thin` tubular wall is produced in al single operation and, as said wall has a substantially uniform thickness throughout, it is no longer necessary to subject said wall to a drawing operation to eliminate the taper in the wall which has.

been produced by the practice of the method heretofore employed. At the saine time, the forcing of the metal through the die by the process of extrusion compacts and densihes the same so asl to substantially eliminate the likelihood of elongated blow holes or gas ockets which become lines of weakness in 11| completed structure. The present process also enables the provision of a closed end wall, or a relatively thick attaching bange, or both, integrally with the tubular wall without causing lines of weakness where the tubular wall joins said end wall or attaching flange while, on the other hand, the extra operations heretofore required in order to supply a llexible wall with a closed end wall or relatively rigid 'attaching flange are avoided.

A method has also been provided whereby thev grain of a relativel thin tubular. wall may be displaced angu arly of the axis of the tube, and at substantially uniform an le throughout the tubular wall. While t 1s method has particular utility when appliedl to di lacing the grain of a tubular wall forme by extrusion or by the combined actionof extrusion and drawing, 1t 1s to be expressly understood that this method of displacing the grain is equally appllcable to l other tubular walls where 1t is desired to displace the ain at an angle to' the axis of the tube an itis therefore to be expressly understood that it is within the contemplation of the present invention toapply this method to d1splacing the grain in tubes which have not been produced by extrusion as Jthe same are moved axially with respect to each other.

While preferred embodiments of the present invention have been described with considerable particularity, it is to be expressly understood that the invention is not restricted thereto, as the invention may be carried out in a variety of ways some of which will now readily suggest themselves' to those skilled in the art.' Reference is therefore to -be had to the appended claims for a definition of the limits of the invention. l

lVhat is claimed is 1. The method of making a flexible corr-ugated tubular wall which includes extruding a blank through a die to forma tubular wall lof substantially uniform thickness and physical characteristics and of the relative thinness suitable for use ina corrugated wall which -is highl flexible in the direction of its axis, and orming flexible corrugations in said tubular wall to render the same hghly flexible in the direction of its axis.

2. The methodof making a flexible corrugated tubular wall which includes extruding ablank through a die to form a relatively thin tubularwall, applying a drawing force to said blank which of itself is insufficient to draw said tube to assist its passage through said die under the actionof 'the force of extrusion, and forming hidhly flexible corrugations in said tubular Wal 3. The method of makingva flexible corrugated tubular wall which includes extruding a blank through a die to form a. relatively thinl tubular wall, displacing the grainv in said tubular wall at an angle to its axis without deformin and substantiall reducing said wall, an then forming hig ly liexible corrugations in said tubular wall.

4. The method of making a flexible corrugated tubular wall which includes extruding a blank through a die to form a relatively thin tubular wall, applying a drawin force' to said blank to assist its 'passage trough said die, dis lacing the grain inthev extruded tubular l wal at an angle to its axis, and thereafter formin highly iexible corrugations in said tubu ar wall.

5. The method of making a flexible corrugated tubular wall which includes extruding a blank through a die to form ay single'operation a tubular wallhavmg substant1ally .the thickness suitable -for forming highly flexible corrugations, and. corrugating the tubular wall to render the same highly flexible in the direction of its axis.

6. The method of making a flexible corrugated tubular wall which includes extruding a blank through a die to orm 1n a slngle 0pryeration .a tubular wall having substantially the thickness suitable for forming highly -flexible corrugations, subjecting said blan to a drawing force simultaneously with the /extruding operation, and corrugating the tubularwall to render the same highly flexible in the direction of its axis.

7. The method of making a flexible corrugated tubular wall which includes extruding a blank through a 'die to form in a sinplace 1ts gram an gle operation a tubular wall having substantially the thickness' suitable for 'forming stantiall the thickness suitable .for forming highly exible corrugations, simultaneously subjecting said blank to. a drawin force,

working the tubular wall todisp ace its grain at an angle to its axis, and thereafter corrugatin the tubular wall` to render the same hig y llexiblein the direction of its axis.

9. The method of making-a flexible corrugated tubular wall which includes form- -ing a relatively thin tubular wall,V moving said wall through a die while causingrelative rotation between said wall and dieto displace the grain at an angle to the axis of said wall without substantially thinning said wall, and thereafter corrugating said tubular wall to render Ithe same flexible in the direction of its axis. i j A t 10. The method of making a lexible corrugated tubular wall which includes extrud- ,ing a relatively thin tubular wall, displacing the grain 1n said tubular wallby passing the same through a die while causmg re1- ative rotation between said wall and die,

and thereafter corruofatingv said tubular wall l to render the sameexible the direction of .its axis. l v

11. The method of making a flexible corrugated tubularI wall which includes simultaneously extruding and drawing a relatively thin tubular wall, displacing the grain in said wall by passing' the same through a die while causing relative rotation between said wall and die, and thereafter corrugating metal wall having relatively deep corrugations therein to render the same lhighly flexible in Athe direction of its axis.

14. Au relatively thin extruded tubular metal wall having relatively deep corrugations therein to render the same hi hly flexible in the direction of its axis, an an end wall integral with said tubular wall.

`15. lA relatively thin extruded tubular metal wall having relatively deep corrugations therein to render the same hi hly lexible in the direction o f its axis, and an end flange integral with and of greater thickness than said tubular wall. f

16. A relatively thin extruded tubular Inetal wall having its grain uniformly displaced at an angle to its axis and provided with relatively deep corrugations to render the same highly flexible in the direction of its axis. e

17. In a method of making flexible corrugated'tubular walls, uniformly displacing the grain angularly of the axis of a relatively thin tubular wall without substantially thinning. the same by forcing4 said wall through a die while produci relative rotation between vsaid wall and `e, and `then forming flexible corrugations in said vtubular wall.

18. The method of making a flexible corrugated tubular wall which 'includes elongating and thinning the tubular wall of a tubular blank by an extruding operation, displacing the grain in said tubular wall at an angleto its axis, and thereafter corrugatin the tubular wall to render the same flexible 1n the direction of its axis.

19. The method of making a flexible corrugated tubular wall which includes forming a relatively thin tubular blank witl1 the grain of the'metal extending parallel to its axis, angularly displacing the grain to a uniform extent throu hout said tubular wall 1n conformity withte robabl'e angularity of the resultant of the ores to which the wall is to be subjected, and forming llexible corrugations in the tubular wall of said blank.

20. The method of making a flexible corrugated tubular wall which includes forming a relatively thin wall by an extruding operation, working the metal,.in .said tubular wall to displace its grain unfo'inly and after forming flexible Icorrugatior'ls in said tubular walll 2l. The method of making :ail flexible eor` rugated tubular Wall which includes forming :L relatively thin ,Wall by an extrudingv operation,w While simultaneously subjecting u said blanl to a diawing force, eWl-king the metal in said tubular wall to displace its grain uniformly and an larly of the axis'l of said Wall, and formln 'flexible corrugtions in said' tubular Wa v i In testimony whereof I have signed this' specification.

WESTON M. FULTON.' 

